is there a way to copy part of pose into another pose
This is old, but the answer will help other people with the same question.

Yes, you can copy part of a pose into another pose. The armatures must be identical. The best way is to create a pose library and save both poses.


Select the pose from which you'll copy a part and go into pose mode.
Select the bones to be copied.
Tip: Hold Ctrl when selecting a parent bone and you'll select all the children.
Ctrl+C or Pose > Copy pose.
Now switch to the pose to be modified. Still in pose mode, Ctrl+V go
to Pose > Paste Pose.